Fabrication of environment-friendly and flexible waterborne epoxy/PVP/h-BN composites for thermal interface material

The solvent-based resins have been applied widely in the preparation of thermal interface material (TIM). However, the use of solvents is harmful to the environment and human health. To address this, an environment-friendly TIM is fabricated by employing waterborne epoxy as a polymer matrix in this research project. The waterborne epoxy resin/polyvinyl pyrmlidone/hexagonal boron nitride (WER/PVP/h-BN) composite is successfully prepared through a facile method. First, the WER/PVP/h-BN mixture is obtained by a one-pot process. Subsequently, the WER/PVP/h-BN composite is fabricated by heat curing. The thermal conductivity of obtained WER/PVP/h-BN composite can reach 1.0921 W/m.K at 40 wt% filler loading. The mechanism of PVP for thermal conductivity enhancement of composites is demonstrated utilizing effective medium theory (EMT) and Fogyel's models. Furthermore, the mechanical, electrical, and surface properties of WER/PVP/h-BN composites are comprehensively investigated. The valuable information and insight for the design and preparation of environment-friendly TIMs are provided in this paper.